PSC16: Avoiding JaggiesHave you ever downsized an image for web use, just to find out that some of your diagonal lines have turned into stair steps, also known as jaggies? This can happen with very contrasty edges or thin black lines in front of a bright background, if they are at certain angles.
On today's Photoshop Corner I'll show you a few methods to avoid those.
Solution 1 - Step Down And Blur
One method that can be helpful is to downsize the image in smaller steps instead of doing it in one go. If you for example have an image that is 3000 pixels wide, size it to 80%, then examine the diagonal lines for any jaggies. If you even see the faintest trace of jagged edges, use the blur tool and slightly blur the jagged edges. Then continue downsizing to 80% again, and so on. At the end you'll have a perfectly downsized image that has smooth diagonal lines. Admittedly, this method is quite work intensive, but for really critical images, it's my main method of making sure everything turns out the way I want.
Solution 2 - Bicubic Smoother
Setting the downsizing method to Bicubic Smoother can also help in less critical cases, even though it is not as effective as the first method. But it sure beats the Step Down method when it comes to speed.
Solution 3 - Layer It When Sharpening
Sometimes jaggies won't show until you finally sharpen your image. Now here's an easy method to avoid jaggies under those circumstances. Duplicate your layer and then apply your sharpening to the copied layer. If you see jaggies, add a layer mask, and paint black over the jaggies with a thin brush. This way the unsharpened, but also unjagged lines will show through and you have successfully avoided the stair steps again.